Average Up

What Does Average Up Mean?
The process of buying additional shares at higher prices. This raises the average price that the investor pays for all the shares. In the context of short selling, averaging up is achieved by selling additional shares at a price higher than that of the first transaction.

Investopedia explains Average Up
Say you buy XYZ at $20 per share, and as the stock rises you buy equal amounts at $24, $28 and $32 per share. This would bring your average purchase price to $26 per share.